diff --git a/package-lock.json b/package-lock.json
index 649463e..082d1dc 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "mailgun-js",
-  "version": "0.22.0",
+  "version": "0.23.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -215,7 +215,7 @@
       "dependencies": {
         "chalk": {
           "version": "1.1.3",
-          "resolved": "http://registry.npmjs.org/chalk/-/chalk-1.1.3.tgz",
+          "resolved": "https://registry.npmjs.org/chalk/-/chalk-1.1.3.tgz",
           "integrity": "sha1-qBFcVeSnAv5NFQq9OHKCKn4J/Jg=",
           "dev": true,
           "requires": {
@@ -1805,9 +1805,9 @@
       }
     },
     "nodemailer": {
-      "version": "4.6.8",
-      "resolved": "https://registry.npmjs.org/nodemailer/-/nodemailer-4.6.8.tgz",
-      "integrity": "sha512-A3s7EM/426OBIZbLHXq2KkgvmKbn2Xga4m4G+ZUA4IaZvG8PcZXrFh+2E4VaS2o+emhuUVRnzKN2YmpkXQ9qwA==",
+      "version": "6.6.1",
+      "resolved": "https://registry.npmjs.org/nodemailer/-/nodemailer-6.6.1.tgz",
+      "integrity": "sha512-1xzFN3gqv+/qJ6YRyxBxfTYstLNt0FCtZaFRvf4Sg9wxNGWbwFmGXVpfSi6ThGK6aRxAo+KjHtYSW8NvCsNSAg==",
       "dev": true
     },
     "normalize-package-data": {
@@ -2593,7 +2593,7 @@
       "dependencies": {
         "minimist": {
           "version": "1.2.0",
-          "resolved": "http://registry.npmjs.org/minimist/-/minimist-1.2.0.tgz",
+          "resolved": "https://registry.npmjs.org/minimist/-/minimist-1.2.0.tgz",
           "integrity": "sha1-o1AIsg9BOD7sH7kU9M1d95omQoQ=",
           "dev": true
         }
diff --git a/package.json b/package.json
index 4d79b14..f38d0e8 100644
--- a/package.json
+++ b/package.json
@@ -36,7 +36,7 @@
   "devDependencies": {
     "clone": "^2.1.2",
     "mocha": "~5.2.0",
-    "nodemailer": "^4.6.8",
+    "nodemailer": "^6.6.1",
     "request": "^2.88.0",
     "sinon": "^7.1.0",
     "standard": "^12.0.0"